Power assembly for grapple or bucket

ABSTRACT

A power assembly for a grapple or clamshell bucket having a plurality of pivoted tines or bucket elements which are actuated to a closed or holding position by hydraulic pressure and which are moved to an open or extended position by compressed gas means, and wherein a single hydraulic hose from the grapple or bucket to a crane or other location of hydraulic power serves for connecting hydraulic power to the grapple.

United States Patent Oscar W. Hahn Houston, Tex. 774,876

Nov. 12, 1968 Apr. 13, 1971 McGinnes, Mfg. Co.

Inventor Appl. No. Filed Patented Assignee POWER ASSEMBLY FOR GRAPPLE 0R BUCKET 7 Claims, 7 Drawing Figs.

US. Cl 294/88, 294/106 Int. Cl ..B25b B66c 1/10 Field of Search 294/69, 70, 71, 72, 88

[56] References Cited UNITED STATES PATENTS 247,829 10/1881 Johnson 294/88 2,877,575 3/1959 Stedt 294/69X 3,104,125 9/1963 Garlinghouse 294/88X 3,228,249 1/ 1966 OBrien 294/69X Primary ExaminerEvon C. Blunk Assistant ExaminerDouglas D. Watts Attorney-Pravel, Wilson & Matthews PATENTED W 31971- SHEET 2 OF 3 flTTORNE YS PATENTED APR 1 3. I97:

SHEET 3 0F 3 OJta/ W Hahn [NI EN TOR Magda PM?! Willow & Maflllewl /l TTORNE YS POWER ASSEMBLY FOR G PLlE Olll BUCKET BACKGROUND OF THE INVENTION The field of this invention is power assemblies for grapples and/or clamshell buckets (hereinafter generally referred to as grappling devices), and particularly grappling devices suspended from a cable system on a crane.

The typical grappling device heretofore suspended from a cable system on a crane has been actuated to open and close same with a multicable sheave assembly. It is difficult, extremely time consuming, and often impossible to change a grappling device on a crane to another size or type on that same crane because of the special construction of such sheave assemblies for a particular size or type of crane, and because of the problems in trying to change the operating cable from one multisheave assembly to another multisheave assembly, running from the grappling device to the cable drum or other handling mechanism on the crane or similar structure. As a result of such problems, the changing of a grappling device on a crane is limited in practical operations, and this means that often a much larger, more awkward grappling device is used than is necessary for handling light or small objects, or other sizes of grappling devices and cranes are utilized, thereby idling valuable and expensive equipment.

Hydraulically actuated grappling devices have been attempted as a possible solution to the problems of the multisheave cable assembly, but so far as is known, these attempts have not been satisfactory or successful, and it is believed that such lack of success was largely due to the use of double or multiple hydraulic hose systems from the grappling device to the boom of the crane which also resulted in a number of problems. For example, with doubleor multiplehose systems, the hoses get tangled with each other as the grapple swings, turns and twists in use, and the hoses cannot be satisfactorily reeled together because of their odd noncircular shape when fastened to each other. Additionally, the extra hose or hoses increases the cost thereof, as well as the weight which becomes a serious obstacle in large installations.

SUMMARY OF THE INVENTION The present invention relates to a power assembly for a grappling device for operation from a crane or similar equipment, wherein pivoted tines or grappling elements are actuated to a closed or grappling position by hydraulic pressure, and wherein compressed gas means is provided for automatically moving the tines or grappling elements to an open or extended position upon a predetermined reduction in the hydraulic pressure supplied to the grappling elements. The direction of action of the hydraulic fluid and the compressed gas may be reversed, so that the hydraulic fluid is used to move the grappling elements to an open position and the compressed gas moves the grappling elements to the grappling position.

With the hydraulic pressure supplied and returned through a single hose, such hose can be readily extended from the grappling device to the crane without tangling or twisting, and can be reeled to vary the length thereof as needed. Further, different sizes of grappling devices constructed in accordance with this invention can be easily used with the same crane in view of the simplicity and ease of attaching to a crane the grappling device using the power assembly of this invention. Additionally, since the full weight of the grappling device is effective when digging, using the power assembly of this invention, a lighter weight grappling device may be used as compared to cable-operated grappling devices digging the same load. This invention also may be readily operated by inexperienced operators in a matter of a few days.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevation illustrating the present invention in use on a typical crane;

FIG. 2 is an elevation of the power assembly of the present invention on a grapple, showing the tines in the closed or grappling position;

FIG. 3 is a vertical sectional view of the grapple of FIG. 2 with the tines in the closed or grappling position;

FIG. 4 is a view similar to FIG. 3, but illustrating the grapple in an open or extended position;

FIG. 5 is an enlarged fragmentary view, partly in elevation and partly in section, illustrating the connection between a center hinge section and the power assembly of this invention;

FIG. 6 is a schematic view of the hydraulic system for the power assembly of this invention; and

FIG. 7 is a fragmentary sectional view illustrating the preferred type of connection of the upper end of the hydraulic cylinder to the head section of the grappling device.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter G designates generally a grapple which is preferably used with a crane C of conventional construction, or any other suitable operating equipment. As will be explained in detail, the opening and the closing of the tines or grappling elements 10 of the grapple G is accomplished with a unique mechanism or power assembly which includes a hydraulic means having a single hose 11 extending from the grapple G to the boom 12 or other part of the crane C. In the usual situation, the hose 11 extends to a conventional reel 14 which is mounted on the boom 12 for maintaining the line 11 essentially taut as the grapple G moves back and forth, and up and down. The grapple G is suspended from a cable 15 of conventional construction which is disposed over the boom 12 and which extends to an operator in the crane C in the known manner for raising and lowering the grapple G. A guideline or cable 16 is connected from the boom 12 to the grapple G to prevent undersired swinging or shifting of the grapple G when in use, as is customary with the type of grapple illustrated herein. The grapple line 16 is formed of wire or wire rope so that it can take any strain exerted by the movements of the grapple G with respect of the boom 12 rather than subjecting the hydraulic line 11 to any such forces. I

Considering the grapple G of this invention more in detail, reference is made in particular to FIGS. 27. The grapple G is illustrated as having eight tines 10 although the particular number may varied, depending upon the size of the grapple G and other factors which are present in a particular installation. When the tines 10 are in the closed position illustrated in FIGS. 2 and 3, the edges of the tines 10 contact each other or are sufficiently close to each other so that together such tines form a bucket. Although the grapple G is illustrated with about eight tines 10, the invention is not limited to use therewith. For example, the power assembly may be used with the type of grappling device commonly referred to as a clamshell bucket, which normally has two bucket elements for confining and moving objects which are disposed within the confines thereof in essentially the same manner as the tines 10. The term grappling device includes a grapple, clamshell bucket and other similar devices with which the power assembly of this invention may be used. The term grappling elements includes the tines It), clamshell bucket elements or any similar structure.

Each of the tines or grappling elements 10 is preferably identical, and as illustrated in the drawings, each tine 10 has a curved L-shaped plate 10a which is tapered to a sharp point 10b. Each tine plate 10a is preferably strengthened by a back brace 10c and suitable tie braces 10d. Each tine 10 has a hinge plate 10c which is pivotally secured to a center hinge section 20.

Although the hinge section 20 may be formed in numerous ways, it is preferably formed with a central cylinder 20a (FIGS. 35) to which are welded or otherwise secured a plurality of support head connecting plates 20b. Such plates 20b are circumferentially disposed with respect to the cylinder 200. A pair of spaced plates 20b are provided for each of the tines with the pivot plate We of each tine 10 disposed between each of said pair of connecting plates b. A pivot pin or bolt 21 extends through each pair of such plates 20b and the pivot plate 10c therebetween so as to establish the pivotal connection of the tines 10 to the hinge section 20. To rigidify and strengthen the center hinge section 20, it preferably has an upper substantially circular reinforcing ring 20c which is welded or otherwise secured to the upper end of the cylinder 20, and also a lower reinforcing ring 20d which is welded or is otherwise secured to the lower end of the cylinder 20a. The connection plates 20b are likewise preferably welded to the rings 20c and 20d.

For limiting the extent of outward pivoting of the tines 10 about their pivot pins 21, each of the tines 10 is preferably formed with a stop projection 10f (FIGS. 3 and 4) which is adapted to engage the ring 200 or any other upper portion of the section 20 as illustrated in FIG. 4.

Each of the tines 10 is formed with a lost motion pivot slot 103 in the back rib or brace 10c for receiving a pivot pin 23 which extends through a fork 25a on the lower end of a link arm 25 which extends upwardly therefrom, as will be explained. The upper end of each link arm 25 is also formed with a fork 25b, each of which is pivotally connected by a pivot pin 27 to a connecting lug 28. The lugs 20 are all circumferentially disposed around a cylinder 29 and are welded thereto. Such lugs 28 and the cylinder 29 form a head section 30, which may also include suitable reinforcing plates 31 and 32. A cable hanger plate 33 is welded or is otherwise secured to the upper end of the plate 31 for connection to the cable 15 or other suitable operating mechanism for raising and lowering the grapple G.

A power means H, which is preferably hydraulic, is connected between the head section and the center hinge section 20. Such power means H includes a cylinder 35 which is pivotally connected at its upper end to the head section 30 by any suitable means, one form of which is illustrated in FIGS. 3, 4 and 7. Thus, the head section 30 has a bracket 36 which is welded or is otherwise secured within the cylinder 29 and which has a suitable opening 360 therethrough for receiving a swivel bearing 37 which in turn has a pivot pin 38 therethrough. The pivot pin 38 extends through lugs 35a at the upper end of the cylinder 35. Thus, the upper end of the cylinder 35 is pivotally connected to the head section 30, but it has limited universal movement provided by the ball type connection 37.

A piston 40 is slidably disposed within the cylinder 35, and it has a piston stem 41 extending downwardly therefrom and through a sealed opening (not shown) in the lower end of the cylinder 35. The piston stem 41 is pivotally connected to the center hinge section 20 (FIG. 35), one type of connection being shown in detail in FIG. 5. Thus, the lower end of the piston stem 41 has a threaded portion 41a which receives a threaded retainer nut 42, a washer 42a and a circular externally curved bearing sleeve 42b. The bearing sleeve 42!; fits into a correspondingly curved bearing housing 43 which is confined within cylinder 200 by a tube or holding element 20d which is locked or welded into place by a plug or plate 20c secured or welded to the lower end of the cylinder 200. Thus, limited universal movement of the section 20 with respect to the stem 41 is permitted by a particular connection illustrated in FIG. 5.

Hydraulic fluid is introduced into the cylinder 35 below the piston 40 by any suitable inlet means such as the inlet connection 45 (FIGS. 3-5) which connects to a flexible or rigid tube 45a extending to the upper end of the head section 30, at which point the flexible hose 11 is connected. The hose 11 is in turn connected to a source of hydraulic fluid in a system such as illustrated in FIG. 6 of the drawing, which will be described in detail hereinafter. On the upper side of the piston 40, a compressed gas means is connected which includes one or more pressure tanks or chambers which are interconnected with suitable tubes 51 and which are also connected to the inlet of the upper end of the cylinder 35. The tanks 50 are supported by any suitable means such as attaching plates 53 which are welded or are otherwise secured to the head section 30 and the upper portions of the tank 50. Gas such as nitrogen or other inert gas is placed in the tank or tanks 50, preferably through a control valve 500 having a pressure gauge 50b therewith. When the piston 40 is at its lowermost position as shown in FIG. 4, the pressure in the chamber 50 is at its lowest amount, but when the piston 40 is moved upwardly by the hydraulic pressure introduced through the inlet 45 from the hydraulic system, the gas within the cylinder 35 above the piston 40 and thus in the tanks 50 is compressed to a greater extent until the maximum compression is reached when the piston 40 has moved to its uppermost position with the tines 10 in the closed or grappling position of FIG. 3.

The hydraulic system of FIG. 6, which may be located in the cab of the crane C, on the grappling device itself, or otherwise suitably disposed for operator control, has the flexible line 11 connected to a valve which is normally manually operated.

' If the hydraulic system is located on the grapple G or other grappling device, it must be small enough to mount above the hinge section 20 and alongside the cylinder 35, and would include a small conventional accumulator (not shown) in line The valve 60 is schematically illustrated in FIG. 6 as having ports 60a, 60b and 60c. When the piston 40 is in the uppermost position as shown in FIG. 3, the valve 60 is in the solid-line position shown in FIG. 6 so that there is fluid communication from the hose 11 through the port 60b of the valve 60 and then through a line 61 to a venturi chamber 62. Actually, due to the compressed gas within the tanks or chambers 50, a release or reduction in the hydraulic pressure beneath the piston 40 would be sufiicient to permit the expansion of the compressed gas and a movement of the piston 40 downwardly for an opening of the tines 10 to the position shown in FIG. 4. However, with the present hydraulic system as illustrated in FIG. 6, an additional fluid reduction is provided in the hydraulic system to increase the speed of opening of the tines 10. This is accomplished by means of a pump P which pumps hydraulic fluid from a storage tank 63 through a line 64 and feeds it through line 65 and port 600 to a venturi 62a within the venturi chamber 62. The pump P is operated by any suitable source of power such as a gasoline engine, diesel engine or electric motor. If the hydraulic system is mounted on the grappling device, the pump is operated by an electric motor (not shown) which is also on the grapple G and which is connected to a source of electric power on the crane or other location.

The flow of the fluid through the venturi 62a creates a reduced pressure in the chamber 62 which causes a rapid movement of the hydraulic fluid from beneath the piston 40 through the line 11, valve 60b, line 61 and the chamber 62.

I The fluid from the chamber 62 then flows through a filter F and a line 66 into the storage tank 63. A relief valve 70 is usually connected in the line 65 for the return of fluid therefrom to the storage tank 63 in the event the pressure in the line 65 becomes excessive.

When it is desired to raise the piston 40 from its lowermost position shown in FIG. 4 to its uppermost position shown in FIG. 3, the valve 60 is moved so as to align the port 600 so that it establishes communication from the line 65 to the line 11, as indicated by the dotted line 60d in FIG. 6. It will be understood that the ports 60a and 60b are no longer in communication with any of the lines when the valve 60 has been shifted to communicate the port 60:! between the lines 65 and 11. When the valve 60 has thus been shifted, either manually or automatically, the fluid from the pump P is transmitted directly to the lower end of the cylinder 35 so as to exert hydraulic pressure upwardly on the piston 40 and move same upwardly against the gas pressure within the cylinder 35. As previously explained, during such upward movement of the piston 40, the gas is compressed into the chamber or chambers 50 for subsequentially automatically returning the piston 40 downwardly when the hydraulic pressure below the piston 40 has been reduced below the pressure provided by the compressed gas within the chamber or chambers 50.

In the operation or use of the grapple G or other grappling device using the power assembly of the present invention, the grappling device is normally suspended from a cable 15 which is operated in the usual manner from the crane C. The hose 11 is preferably reeled on a conventional reel 14 having a spring mechanism for maintaining the hose ll relatively taut and which is connected by suitable hoses extending to the hydraulic system such as that schematically illustrated in FIG. 6 of the drawing. The operation of the present invention is simplified compared to prior constructions since the operator simply moves the valve 60 to either the position with the solidline port 600 or the dotted line port 60d to accomplish either an opening or a closing of the tines of the grapple G, as previously explained.

As will be understood, the grapple G is maintained in its open position as it is swung by the cable 15 to a location over an object to be picked up. Then, with the object disposed below the tines 10 in the position shown in FIG. 4, hydraulic fluid is introduced into the cylinder 35 below the piston 40 is previously explained to move the tines 10 to the closed or grappling position of FIG. 3. It will be understood that the tines 10 do not have to completely close to the position of FIG. 3 to grip an object since the points 1017 may engage the object and lift the same in that manner. In any event, by simply moving the valve 60, the operator may control the opening and closing of the tines 10 of the grapple G.

Since the hose 11 is a single hose, it may be readily reeled and unreeled with respect to the reel 14, and it does not become tangled or twisted during use. The guide cable 16 limits the extent of twisting and horizontal movement of the grapple G during use, as is understood by those skilled in the art. Also, the cable 16 limits any swinging forces of the grapple G so that the hose 11 is not ruptured in the event the grapple G swings when moving it from one position to another.

The grapple G may be connected to any crane C or similar operating equipment having a hydraulic system by simply attaching the grapple G to a cable such as the cable 15 and attaching the hose 11 to a hydraulic system such as the hydraulic system shown in FIG. 6. Thus, a particular crane C may use any one of a number of different sizes of the grapple G, whereby the grapple G may be readily interchanged for handling different sizes of objects by the same crane C or similar equipment.

Iclaim:

l. A power assembly adapted to be used with a grappling device having a plurality of grappling elements, a center hinge section, and means pivotally connecting the upper ends of each of said grappling elements to said center hinge section,

with the upper ends of said grappling elements adapted to pivot to and from an extended position and a closed or grappling position, comprising:

a. hydraulic means for pivoting said grappling elements from one of said positions to the other of said positions;

b. compressed gas means for pivoting said grappling elements from said other of said positions to said one of said positions;

c. said hydraulic means includes a piston disposed in a cylinder with a piston stem extending from the cylinder;

d. means connecting said piston stem to said center hinge section;

e. means for developing hydraulic pressure in said cylinder on one side of said piston for moving same to pivot said grappling elements from said one of said positions to said other of said positions;

f. said compressed-gas means includes a tank of gas connected to the opposite side of said piston from said one side which is subjected to the hydraulic pressure; and

g. the gas in said tank being compressed when said piston is moved to pivot said grapplintg elements from said one of said positions to said other 0 said positions for thereafter automatically effecting a movement of the piston in the opposite direction by such compressed gas when the hydraulic pressure is reduced to an amount lower than the pressure of the compressed gas.

2. The structure set forth in claim 1, including:

a. a single hydraulic fluid inlet to said cylinder, and

b. a single hose connected from said inlet to a source of hydraulic fluid pressure.

3. The structure set forth in claim 1, wherein said grappling device includes a head section disposed above said tine support head and a link arm pivotally connected to said head section and an intermediate portion of said grappling elements 'for effecting an outward pivoting of said grappling elements for effecting an outward pivoting of said elements to an open position upon a downward movement of said hinge section relative to said head section.

4. The structure set forth in claim 3, wherein said head section has means therewith for attaching a suspending cable thereto for suspending the grappling device.

5. The structure set forth in claim 1, including:

a. a single hose extending from said hydraulic means; and

b. reel means for reeling said hose thereon.

6. The structure set forth in claim 1, wherein:

a. said one of said positions is an open or extended position of said grappling elements; and i b. said other of said positions is a closed or grappling position of said grappling elements.

7. The structure set forth in claim 1, wherein said hydraulic means includes a hydraulic system having a venturi therein for providing a rapid opening of the grappling elements. 

1. A power assembly adapted to be used with a grappling device having a plurality of grappling elements, a center hinge section, and means pivotally connecting the upper ends of each of said grappling elements to said center hinge section, with the upper ends of said grappling elements adapted to pivot to and from an extended position and a closed or grappling position, comprising: a. hydraulic means for pivoting said grappling elements from one of said positions to the other of said positions; b. compressed gas means for pivoting said grappling elements from said other of said positions to said one of said positions; c. said hydraulic means includes a piston disposed in a cylinder with a piston stem extending from the cylinder; d. means connecting said piston stem to said center hinge section; e. means for developing hydraulic pressure in said cylinder on one side of said piston for moving same to pivot said grappling elements from said one of said positions to said other of said positions; f. said compressed-gas means includes a tank of gas connected to the opposite side of said piston from said one side which is subjected to the hydraulic pressure; and g. the gas in said tank being compressed when said piston is moved to pivot said grappling elements from said one of said positions to said other of said positions for thereafter automatically effecting a movement of the piston in the opposite direction by such compressed gas when the hydraulic pressure is reduced to an amount lower than the pressure of the compressed gas.
 2. The structure set forth in claim 1, including: a. a single hydraulic fluid inlet to said cylinder; and b. a single hose connected from said inlet to a source of hydraulic fluid pressure.
 3. The structure set forth in claim 1, wherein said grappling device includes a head section disposed above said tine support head and a link arm pivotally connected to said head section and an intermediate portion of said grappling elements for effecting an outward pivoting of said grappling elements for effecting an outward pivoting of said elements to an open position upon a downward movement of said hinge section relative to said head section.
 4. The structure set forth in claim 3, wherein said head section has means therewith for attaching a suspending cable thereto for suspending the grappling device.
 5. The structure set forth in claim 1, including: a. a single hose extending from said hydraulic means; and b. reel means for reeling said hose thereon.
 6. The structure set forth in claim 1, wherein: a. said one of said positions is an open or extended position of said grappling elements; and b. said other of said positions is a closed or grappling position of said grappling elements.
 7. The structure set forth in claim 1, wherein said hydraulic means includes a hydraulic system having a venturi therein for providing a rapid opening of the grappling elements. 